4006 – ASCA IgA

The ASCA IgA is a quantitative immunoassay for the determination of IgA antibodies against Saccharomyces cerevisiae in human serum. The ASCA IgA is intended as an aid in the diagnosis of Crohn´s disease in conjunction with other clinical and laboratory findings.

Non-specific inflammatory bowel disease including Crohn’s disease (CD) (Enteritis regionalis) and ulcerative colitis (UC) are characterised by chronic-remitting inflammatory processes of the intestine. Immunologic, genetic, infectious and environmental factors have been identified as the risk factors of developing one of these diseases. An important serological marker for the differential diagnosis of Crohn’s disease is the determination of IgA and IgG antibodies to Saccharomyces cerevisiae, which are highly prevalent (70 %) in patients with CD and atypical antineutrophile cytoplasmatic antigens (aANCA).  Thus, ASCA, in combination with the detection of autoantibodies to atypical anti-neutrophil cytoplasmic antigens (aANCA), are a valid parameter for the differentiation of Crohn’s disease and ulcerative colitis.

The ELISA (Enzyme Linked Immunosorbent Assay) is an immunoassay for the determination of specific antibodies. The strips of the microtiter plate are coated with test-specific antigens. If antibodies are present in the patient´s sample, they bind to the antigens. A secondary antibody conjugated with the enzyme peroxidase detects the generated immune complex. A colorless substrate is converted into the colored product. The signal intensity of the reaction product is proportional to the antibody activity in the sample. After stopping the signal intensity of the reaction product is measured photometrically.

The immunoassay is designed for manual professional in vitro diagnostic use.